Thomas shaw



(No Model.) 2 Sheet-Sheet 1.

. T. S H A W.

Hydraulic- QIiShiOII-BHffGITOI Railroads No. 240,044. Patented April I2, 1881.

WITNESSES: j/VVENTOR A TTORN y N PETERS, PNOTO-LITHOGEAPHER. WASHINGTON, D Q

(No Model.) I 2'Sheets--Sheet 2 T. S H A W.

Hyd r aulic Cushion Buffer for Railroads. No. 240,044 I PateptedApril'l2,1881

gllilliii [NI/ENTER WITNESSES;

A TTORNEI/ UNITED STATES THOMAS SHAW, OF PHILA:DELPH1A, PENNSYLVANIA.

HYDRAULIC CUSHION-BUFFER FOR RAILROADS.

SPECIFICATION forming part Of Letters Patent No. 240,044, dated April 12, 1881.

Application filodJanuary29, 1881. (No model.) 7

To all whom it may concern:

Be it known that I, THOMAS SHAW, of the city and county of Philadelphia, Pennsylvania, have invented a new and Improved Hydraulic Cushion-Buffer for Railroad-Termin als and other Purposes; and I hereby declare the following to be a full, clear, and exact description of the same, reference being had to the accompanying drawings, and to the letters of reference marked thereon. V

My invention consists in the provision of a hydraulic cylinder and piston or plunger provided with a safety-valve loaded to any maximum load, so that a predetermined maximum resistance is offered from the beginning to end of stroke of piston or plunger, arranged and operated in the manner and for the purpose hereinafter described.

The object of the invention isto overcome the momentum of moving trains of cars or other heavy bodies in motion without destructive eftectyand to enable locomotives and steamtugs to pull heavy loads in a speedy and jerky manner without destructive effect, as hereinafter explained.

In order to enable others to use and practice my invention, I will proceed to describe its construction and operation.

On reference to the accompanying drawings,

which form part of this specification, Figure 1 t represents a vertical section of the cushionbuffer as applicable to terminals of railroads, of which 0 is the rail of an ordinary railroad, resting upon sleepers p, which rest upon a beam of channel-iron, 'n, which is the foundation-beam of the appliance, and from this beam are erected two vertical pillars, l, of the same channel-beam, secured by rivets or bolts to beam at, and thoroughly braced by cast-metal braces m, as shown, all of which gives firm support to a metal hydraulic cylinder, a, a heavy square head being provided at r for bolting to said pillars Z. The height of said hydraulic cylinder is the same as the platform of the cars above the track 0. The said cylinder to is provided with an ordinary cylinderhead at r, with a central bore for the passage of piston or plunger rod t through the same when pressing upon piston v against resistant fluid in cylinder a. Said piston 22 is provided with ordinary hydraulic or other pack- 1119;.

b is a valve-box for operation of safety-valve 0c, and c is a dome-cover containing which presses upon valve .90 more or bly under control of a set-screw, d, for regulating the same. Said valve-box and dome cap are secured in place by bolts through the flanges shown. Said dome-cap c is provided with an outlet-pipe, e, that leads to any suitable tank located above the cylinder a, and f is an inlet-pipe leading from same tank to valve-box b or cylinder 61, for the purpose of insuring a full cylinder of fluid under the pressure due to the height of the tank, which pressure should be always great enough to propel piston c outward when unresisted by any load other than its own frictional resistance. Said pipe f is provided with ordinary check-valve, g, openingin ward. A heavy metal head, It, is provided on the outer end of piston or plunger rod 2', for the purpose of offering large surface to the blow of bumpers on the cars. This head, when very weighty, can be guided by an ordinary cast-metal yoke or crosshead reaching down to the track and provided with suitable Wheels on each side to run upon the track and support the weight and guide p 2/, less foreithe same.

The railroad-terminal buffer is operated in this wise: The aforementioned tank is filled withfiuid (glycerine is preferred) in sufficient quantity to more than fill the connecting-pipes and cylinder a. The elevated tank can be at any height that will cause sufficient pressure to propel piston o and rod i outward, at which time the buffer is in condition to receive a blow from any moving body against the, head It. The valve or having been previouslyweighted to some predetermined pressure-for example, two hundred pounds per square inch-this piston having an area of thirty square inches, there will be offered in that case a maximum resistance of six thousand pounds for a dis- 'tance of length of stroke of plunger-rod i, 5 which will be from four to ten feet, according to work to be performed, rendering the buffer competent to overcome the momentum of heavy nioving bodies without destructive efi'ect by virtue of the long-continued maximum resist- 10o ance of plunger from the beginning to the end of stroke. The maximum resistanceis set sufficiently low so as not to produce destructive effect upon the stationary supports provided, or the timbers, 850., of the moving body in which the momentum is to be overcome. The strength, 860., of the materials employed will have to be calculated for each case according to the work to be performed.

The advantage of this buffer in overcoming the momentum of heavy moving bodies becomes evident when it is taken into consideration that a blow of five hundred tons when arrested in a space of one inch becomes a blow of less than eight tons when arrested in a space of sixty-four inches, and to arrest the same blow in double that distance gives a resultant of only half the pressure (four tons) required of the buffer.

it will be observed that the four or eight tons pressure could be received without de' structive effect, while the five -hundred-ton blow would produce violent destruction on the same timber or metal supports, including the breakage of the movin g body..

Fig. 2 shows the same device differently arranged for another character of load, where a ullin action occurs as in shi )S or tu ca-' bles or pulling-ropes of locomotives. in this case the buffer is operated in this wise: The hydraulic cylinder (0 is provided with the piston 15, secured to rod 2', that passes through cylinder-head r, and terminates in ring-head 7c. The cylinder-head r is secured to flanges of cylinder at by boltsin the manner shown, and

ordinary hydraulic packing shown secures a' tight jointwhere piston-rod passes through head 1'. A projecting metal ring, g, limits the stroke of piston toward said head r. A pipe, h, provided with any suitable check valve opening inward, leads from any source of fluidpressurethe water of a steam-boiler or a steam-pump, for instance-and a safety-valve, c, of annular configuration closes on an annular passage in piston 17, the valve being pressed in place by spring a, and the screw-nut d on the inner end of piston-rod i. The pressure of said spring is regulated according to a predetermined maximum load before bolting on cylinder-head b. A pipe, 6, leads from cylinderhead I) overboard or to any suitable tank, for catching fluid escaping from rear of cylindera on the back stroke of same.

8 s are ordinary brackets cast on metal cylinder a, to enable the bolting of same to deck or other suitable place where it is desired to pull from in the manner hereinafter described.

This form of bufferis operated in this wise: The cylinder a, after being secured to (leek of boat or to any part of a locomotive or other moving body, is filled with water or other suitable fluid from any source of pressure through pipe h, and when said cylinderis full and the safety-valve 0 previously loaded to any desired pressure by spring u and nut 61, the buffer is in a condition to be operated, and any rope or chain cable can be attached to ring-head k and to any other separate body. When any prolonged motion of the boat or locomotive carrying the cylinder a pulls upon the cable (connected with ring-head of pistonrod 1') with all the force that equals the acquired. momentum of the moving body, the cable will receive only so much load as was predetermined by the setting of the said safety-valve 0, but for a prolonged period of time, until the moving body is gradually brought to rest under the constant maximum strain provided'in this case, the effect of which is to haul off any other body susceptible of movement under the great strain here provided without the usual destructive effect upon the cables or parts connected therewith, thus enabling steam-tugsand wrecking-locomotivcs to always pull fearlessly to the predetermined maximum force, including the momentum of the moving mass, without the usual destructive effect that usually attends this operation.

It is evident that the described cylinder and attending piston and plunger rods can be variously fashioned and the valves and pipes variously located without any alteration in the result. I therefore do not wish to confine myself to the exact configuration shown; but

What I do claim, and desire to secure by Letters Patent, is

In hydraulic cushion-buffers, the combination, with a suitable supporting frame-work or bed of the buffer, of a hydraulic cylinder, and the described piston or plunger, and a safety-valve or equivalent device, set to any maximum load, so that a predetermined maximum resistanceis offered to a piston or plunger arranged and operated with fluids in the manner described, and for the purpose set forth.

THOMAS SHAW.

Witnesses WM. GARWOOD, W. B. HUGHES. 

